Preliminary Bat Roost Assessment and Bird Survey for, Mr. and Mrs. Ball. Building adjacent to, The Coach House, Holly Grove Farm, LONGNOR, Derbyshire, SK17 0NF.

Map Ref SK 0624 6339 3rd September 2020.

S. Christopher Smith MRICS MSc CEnv. The Hayloft, Farm Lane, Grendon, ATHERSTONE, Warwickshire. CV9 3DR

Mobile

Natural England License Number 2016-23395-CLS-CLS Natural England Bat Mitigation Class License Registered Consultant RC133

©Tamworth Property Services. Summary.

- There is one butterfly wing fragment at first floor which may possibly be evidence of Brown long eared bats using the buildings as a place of shelter.
- There was evidence of swallows and wrens nesting at ground floor in the building.
- There is a poor roosting opportunity under the ridge tiles of the property which will not be affected by the proposed change of use as the roof will not be removed.
- There is a roosting opportunity against the ridge board and in crevices in the stone walls at first floor.
- This roosting opportunity is poor due to regular human use of this space and both artificial and natural lighting.
- An emergence survey and remote detection equipment left within the building did not produce any evidence of bats roosting in the building.
- New roosting opportunities for bats can be created by installing a bat box into the adjacent barn where there is also ridge board roosting available.
- The conversion of the building to a dwelling, if approved by the Local Authority must not occur if birds are nesting in the building until the young have fledged.
- New nesting opportunities for swallows and wrens will be retained in the adjacent barn and for swallows in the coal bagging plant.
- A method of working must be put in place with contractors to ensure that in the event of bats being found they will not be injured. Introduction.

An inspection and building survey for bats was requested by Rob Duncan Planning Consultancy Limited on behalf of Mr. and Mrs. Ball. The survey was to be undertaken in relation to the submission of a planning application to convert the existing barn building to a new dwelling. The property was visited on the 15th July 2020 and the surveyor spent 1 hour on site.

Temperature; 12°C Wind; 1-2 Beaufort Scale Cloud Cover; 8/8th. There was light rain during the survey.

Legislation concerning bats.

The Wildlife and Countryside Act 1981 (WCA) protects bats and their roosts in England, Scotland and Wales. Some parts have been amended by the Countryside and Rights of Way Act 2000 (CRoW) which applies only in England and Wales, and by the Nature Conservation (Scotland) Act 2004 which applies in Scotland.

The Conservation and Habitats Regulations 2010 (better known as the Habitats Regulations) implements the Council Directive on the Conservation of Natural Habitats and of Wild Fauna and Flora. All bats are listed as 'European protected species of animals'.

Under Regulation 41 of the Conservation of Habitats and Species Regulations 2010 it is illegal to:

- Deliberately capture, injure or kill any wild animal of a European Protected Species (EPS),
- Deliberately disturb wild animals of an EPS (affecting ability to survive, breed or rear young) – disturbance of animals includes in particular any disturbance which is likely to impair their ability to survive, to breed or reproduce, or to rear or nurture their young, • Deliberately disturb wild animals of an EPS (impairing ability to migrate or hibernate) – disturbance of animals includes in particular any disturbance which is likely to impair their ability in the case of hibernating or migratory species to hibernate or migrate,

• Deliberately disturb wild animals of an EPS (affecting local distribution and abundance) – disturbance of animals includes in particular any disturbance which is likely to affect significantly the local distribution or abundance of the species to which they belong,

• Deliberately disturb wild animals of an EPS (whilst occupying a structure of place used for shelter or protection) – intentionally or recklessly disturb any wild animal while it is occupying a structure or place which it uses for shelter or protection,

• Damage or destroy a breeding site or resting place of a wild animal an EPS.

Under the Wildlife and Countryside Act 1981 (as amended) it is illegal to:

• Recklessly or intentionally kill, injures or take any wild animals included in Schedule 5.

• Recklessly or intentionally damage or destroy, or obstruct access to any structure or place which any wild animal included in Schedule 5 uses for shelter or protection,

• Recklessly or intentionally disturb any such animal while it is occupying a structure or place which it uses for shelter or protection.

Legislation concerning birds.

All common wild birds are protected under The Wildlife and Countryside Act 1981 (and as amended). Under this legislation it is an offence to:

• kill, injure or take any wild bird

• take, damage or destroy the nest of any wild bird while it is in use or being built

• take or destroy the egg of any wild bird

Certain rare breeding birds are listed on Schedule 1 of The Wildlife and Countryside Act 1981 (and as amended). Under this legislation they are afforded the same protection as common wild birds and are also protected against disturbance whilst building a nest or on or near a nest containing eggs/unfledged young.

Methodology for bats.

The building surveys have been undertaken in accordance with Bat Surveys for Professional Ecologists- Good Practice Guidelines, 2016, the Bat Conservation Trust. Surveys of the buildings were undertaken during the daytime to look for evidence of bats using the buildings, or likely roosting sites. The evidence of bats using a building as a place of shelter can include bat droppings, grease marks, urine stains or actual bats. This evidence is then considered when planning evening emergence counts and activity surveys, using bat detectors. These surveys provide evidence of where bats are roosting and activity across the site by foraging or commuting bats. The Bat Surveys for Professional Ecologists- Good Practice Guidelines, 2016, specify that emergence surveys are undertaken dependent upon the roost potential of the buildings on the survey site, as set out below;

| Roost potential. | Number of surveys. | |------------------|--------------------| | High. | 3 | | Low to moderate. | 2 | | Low. | 1 |

The surveys are started at sunset, with bats emerging from roosts at different times, dependent upon the species, and continued for two hours. Emergence surveys can only be undertaken from the beginning of April to the end of September when bats are active. The optimum period of undertaking surveys is the beginning of May to the end of August. Their emergence is dependent upon the weather, the bats only leaving their roost on warm nights when there will be sufficient insect prey around to make flight worthwhile. While bats will emerge in light rain and moderate winds, the surveys would not be undertaken when there is heavy rain and/or strong winds as this would not provide reliable data upon which to base the conclusions of the surveys. Mild weather in April and September will produce bat activity, particularly providing information on forage areas, commuting routes and pre-maternity group roosting.

Any trees on site are surveyed following the methodology set out in the Bat Tree Habitat Key, Henry L Andrews et al 2013, which produces a key for identifying Potential Roost Features in trees and their likelihood of being used by bats. Trees on any site being surveyed will have Potential Roost Features identified from ground level surveys and highlighted in the report.

**Bat records and habitats.**

A search of public records has revealed the presence of the following bats within 3km of the site;

- Myotis daubentonii.
- Myotis mystacinus.
- Myotis Nattereri.
- Nyctalus noctula.
- Pipistrellus pipistrellus.
- Pipistrellus pygmaeus.
- Plecotus auritus.

A search of the DEFRA MAGIC Dataset shows that there are no habitats adjacent to the site which of a special nature conservation status or significance. There is agricultural land surrounding the site. There is the area of Leek Moors Site of Special Scientific Interest to the west of the site. This comprises areas of Upland Flashes, fens and Swamps., Upland Heathland and Purple Moor Grass and Rush Pasture. The site falls within the National Habitat Network All Habitats Combine Network Expansion Zone. A search of the DEFRA MAGIC Dataset shows that the site falls inside of a Farm Wildlife Package area where there is support for Lapwings and Curlews through Countryside Stewardship targeting. The site does not fall into the buffer zones around the Deciduous Woodlands where there is support for Priority Woodland Bird Species; Lesser Spotted Woodpecker, Tree Pipit, Redstart, Wood Warbler, Spotted Flycatcher, Pied Flycatcher, Marsh Tit, Hawfinch, Lesser Redpole. The Leek Moors Site of Special Scientific Interest is to the west of the site. There are no other biodiversity enhancement areas adjacent to the site. A search of the DEFRA MAGIC Dataset shows that there have been a number of European Protected Species licenses granted locally. None of the sites is adjacent to the property being surveyed.

| Species. | Destruction of or damage to a breeding site for bats. | Destruction of or damage to a resting place for bats. | |----------|------------------------------------------------------|------------------------------------------------------| | Common pipistrelle bats | No | Yes | | Common pipistrelle bats. | No | Yes | | Common pipistrelle, Whiskered, Natterer’s bats. | Yes | Yes | | Common pipistrelle bats. | yes | Yes | | Common pipistrelle, Brown long eared bats. | No | Yes | | Brown long eared, Common pipistrelle bats. | No | Yes | The Coach House.

Constraints.

The building survey was undertaken in the summer when evidence of bats internally can still be seen but external evidence may be unavailable after heavy rain. There was a light rain on the day of the survey. The surveyor does not believe that the weather masked any evidence or access points for bats. There were no constraints to the surveyor for access in the building survey for bats. The survey was undertaken during the Covid-19 period of social distancing but there were no constraints to the surveyor for access in the building survey for bats. Building Survey.

The buildings to be surveyed consisted of a two storey stone barn with a pitched roof.

The site has low value to biodiversity and comprises hard standing and buildings. Proposed plans include the creation of gardens with amenity grassland, trees and ornamental shrubs which will result in an increase in biodiversity for the site.

The results of the building survey are presented as the likelihood of bats using an area/feature;

- **None.** Bats are unlikely to use the feature/area in any way.
- **Poor.** Bats may use the feature/area but it is not thought to be likely.
- **Possible.** The feature/area provides an area that may be used by bats but no direct evidence of occupation was found. **Definite.** Clear evidence of the use of a feature/area as a place of shelter, such as droppings.

| Feature. | Evidence of bats. | Likelihood of bats roosting. | Photograph. | |---------------------------|-------------------|------------------------------|-------------| | Behind ridge board. | None. | Possible. There is access to the roof space for bats. | ![Photograph](image1.jpg) | | In splits in timber rafters. | None. | None. Machine cut timbers. | ![Photograph](image2.jpg) | | Feature. | Evidence of bats. | Likelyhood of bats roosting. | Photograph. | |------------------|-------------------|-----------------------------------------------------------------------------------------------|-------------| | Under ridge tiles.| None. | Poor. There is a possible access to the underside of the ridge tiles for bats but the lead under cloaking makes use by bats unlikely. | ![Photograph](image1.jpg) ![Photograph](image2.jpg) ![Photograph](image3.jpg) ![Photograph](image4.jpg) | | Feature. | Evidence of bats. | Likelyhood of bats roosting. | Photograph. | |--------------------------|-------------------|------------------------------|-------------| | Under loose or missing roof tiles. | None. | None. The plain tiles and stone slab tiles have no access points for bats. | ![Image](image1.jpg) | | In eaves. | None. | None. Stone eaves with no access for bats. | ![Image](image2.jpg) | | Feature. | Evidence of bats. | Likelyhood of bats roosting. | Photograph. | |----------|-------------------|-----------------------------|-------------| | In verge. | None. | None. There is no access for bats. | ![Photograph](image1.jpg) ![Photograph](image2.jpg) ![Photograph](image3.jpg) ![Photograph](image4.jpg) | | Feature. | Evidence of bats. | Likelyhood of bats roosting. | Photograph. | |----------|-------------------|-----------------------------|-------------| | In crevices in the stone walls externally. | None. | None. There is no access for bats. | ![Photograph](image1.jpg) | | In crevices in the stone walls internally. | A single butterfly wing fragment was found on the stone wall. This may be a feed fragment from a bat or from the swallows that are using the ground floor of the building for nesting. | Possible. There is access for bats to the first floor where there are some poor crevices for use by bats. Some pass through the wall and two provided crevice roosting but no evidence of bats was found when checked with an endoscope. | ![Photograph](image2.jpg) | | Feature. | Evidence of bats. | Likelihood of bats roosting. | Photograph. | |---------|------------------|-----------------------------|-------------|

Bat-survey.co.uk Emergence surveys.

In order to provide data upon bat movements on site, to determine whether bats are roosting in buildings and to allow the identification of bats emerging from buildings, one evening emergence survey was undertaken. The number of surveys undertaken on each building was determined with reference to the Bat Survey Guidelines for properties with low roost potential. A remote bat detector and Trail cam were put in the first floor area recording any bat activity.

The aim of each survey was to look at different areas of the buildings to determine if bats were emerging from a roost and to assess bat activity across the site. The surveys were undertaken using heterodyne and frequency division bat detectors from which it is possible to identify bats by their different ultrasound call. Separate bat passes are recorded where the echolocation ends for more than 5 seconds. Where a bat was seen it was recorded on a plan of the site to provide information upon movements across the site. As bats close in on their prey their echolocation calls get closer together sounding like a buzz. These feeding buzzes are recording as they confirm the presence of prey and bats feeding in the area.

During the Covid 19 period of lockdown and social distancing the need to keep surveyors safe and avoid the risk of infection resulted in the decision to restrict access to the site to a single surveyor and for that surveyor to work their way around the site looking at different areas of the buildings where there was access for bats or roosting opportunities for bats. Because of this, surveys were undertaken sometimes on consecutive days or only a week apart. There was no repeat survey of the same feature at anything less than two weeks apart to ensure that the surveys of repeat areas met the requirements of the Bat Survey Guidelines.

The surveys were undertaken using Batbox Duet frequency division bat detectors with an Edirol R09 recording device, a Batbox Baton XD Time Expansion bat detector with Olympus wav recorder, an Elekon Batscanner and Magenta 5 heterodyne bat detectors.

1st September 2020.

Sunset. 20.55 Air Temperature. 15.2°C at the start of 13.1°C at the end of the survey. Wind. Beaufort Scale 0-1. Cloud cover. 2/8th.

Survey started 20.50 and ended at 21.52.

Surveyor. S. Christopher Smith.

| Time | Direction | Activity | Species. | Notes. | |-------|-----------|-----------|-------------------|-----------------| | 20.26 | A + B | Foraging | Common pipistrelle| Foraging until 20.30 | | 20.31 | B + C | Foraging | Common pipistrelle| 2 passes | | 20.32 | C | Foraging | Common pipistrelle| 2 passes | | 20.32 | D | Foraging | Common pipistrelle| | | 20.33 | E | Foraging | Common pipistrelle| | | 20.35 | D | Foraging | Soprano pipistrelle| 2 bats | | Time | Status | Species | Notes | |-------|---------|------------------|------------------------| | 20.38 | B | Foraging | Common pipistrelle | | 20.40 | Not seen| Foraging | Common pipistrelle | 3 passes | | 20.41 | E | Foraging | Common pipistrelle | 2 passes | | 20.46 | Not seen| Commuting | Common pipistrelle | 4 passes | | 20.48 | Not seen| Foraging | Common pipistrelle | 4 passes | | 20.49 | Not seen| Foraging | Common pipistrelle | 2 passes | | 20.50 | Not seen| Commuting | Common pipistrelle | Foraging until 20.52 | | 20.50 | Not seen| Foraging | Common pipistrelle | 2 passes | | 20.55 | Not seen| Commuting | Common pipistrelle | Foraging until 20.27 | | 20.56 | Not seen| Foraging | Common pipistrelle | 5 passes | | 20.59 | Not seen| Foraging | Common pipistrelle | 3 passes | | 21.00 | Not seen| Foraging | Common pipistrelle | 4 passes | | 21.01 | Not seen| Foraging | Common pipistrelle | Foraging until 21.05 | | 21.04 | Not seen| Foraging | Common pipistrelle | 4 passes | | 21.08 | Not seen| Commuting | Common pipistrelle | 2 passes | | 21.10 | Not seen| Commuting | Common pipistrelle | 2 passes | | 21.12 | Not seen| Commuting | Common pipistrelle | Foraging until 21.14 | | 21.13 | Not seen| Foraging | Common pipistrelle | | 21.15 | Not seen| Commuting | Common pipistrelle | | 21.15 | Not seen| Foraging | Common pipistrelle | 3 passes | | 21.18 | Not seen| Commuting | Myotid | | 21.19 | Not seen| Commuting | Common pipistrelle | | 21.23 | Not seen| Commuting | Common pipistrelle | | 21.24 | Not seen| Commuting | Common pipistrelle | 3 passes | | 21.27 | Not seen| Commuting | Common pipistrelle | 2 passes | | 21.35 | Not seen| Commuting | Common pipistrelle | 2 passes | Surveyor. Katy Smith, trainee bat worker.

| Time | Direction | Activity | Species | Notes | |-------|-----------|---------------------------|--------------------------|----------------------------| | 20.13 | A | Entered and then emerged from stables | Common pipistrelle | | | 20.15 | A | Entered and then emerged from stables | Common pipistrelle | | | 20.20 | B | Foraging | Common pipistrelle | | | 20.27 | B | Foraging | Common pipistrelle | Foraging until 20.28 | | 20.28 | B | Foraging | Common pipistrelle | | | 20.29 | B | Foraging | Soprano pipistrelle | | | 20.31 | B | Foraging | Common pipistrelle | | | 20.32 | B | Foraging | Common pipistrelle and Soprano pipistrelle | 2 bats | | 20.36 | B | Foraging | Common pipistrelle | 2 bats | | 20.39 | B | Foraging | Common pipistrelle | Foraging until 20.41 | | 20.46 | Not seen | Foraging | Common pipistrelle | | | 20.47 | Not seen | Foraging | Noctule | | | 20.48 | B | Foraging | Common pipistrelle | | | 20.50 | B | Foraging | Common pipistrelle | | | 20.51 | B | Foraging | Common pipistrelle | 2 bats | | 20.53 | Not seen | Foraging | Common pipistrelle | | | 20.56 | B | Foraging | Common pipistrelle | | | 20.59 | B | Foraging | Common pipistrelle | | | 21.01 | Not seen | Foraging | Common pipistrelle | | | 21.04 | Not seen | Foraging | Common pipistrelle | | | Time | Status | Activity | Species | |-------|----------|----------|------------------| | 21.09 | Not seen | Foraging | Common pipistrelle | | 21.12 | B | Foraging | Common pipistrelle | | 21.13 | B | Foraging | Common pipistrelle | | 21.16 | Not seen | Foraging | Common pipistrelle | | 21.19 | Not seen | Foraging | Common pipistrelle | | 21.23 | Not seen | Foraging | Common pipistrelle | | 21.24 | Not seen | Foraging | Common pipistrelle | | 21.26 | Not seen | Foraging | Common pipistrelle | | 21.27 | Not seen | Foraging | Common pipistrelle | | 21.35 | Not seen | Foraging | Common pipistrelle |

No bats were seen on the Trail camera or on the remote bat detector which were left in the first floor from the date of the initial survey, 15th July, to the 1st September 2020.

Analysis of the recordings from the bat detectors have confirmed the presence of Common Pipistrelle bats and Soprano pipistrelle bats.

The bats were commuting across the site with forage calls recorded. The sonogram shows the typical ‘hockey stick’ shape for all pipistrelle echolocation calls, an initial frequency modulated downwards sweeping call followed by the constant frequency peak frequency area. The peak frequency can be seen to be around 45kHz on the peak frequency graph, confirming that the bat was a Common Pipistrelle. The Soprano Pipistrelle bats heard have also been confirmed by sound analysis with the peak frequency being around 55kHz. These were fainter than the Common pipistrelle recordings indicating they were further away. A Noctule bat was also heard on site but this was faint, indicating it was some distance away. Noctule sonogram.

Noctule peak frequency. Birds.

There was evidence of birds nesting in the barn at ground and there are opportunities for birds to nest in the building at first floor.

Swallows are nesting at ground floor with one old swallow nesting having been taken over by Wrens. Conclusion.

There was one butterfly wing fragment found at first floor on the stone wall. This may be a feeding fragment from a Brown long eared bat or may be from the swallows that are nesting at ground floor. There was one possible piece of evidence of bats using the building as a place of shelter. This roosting opportunity is poor due to regular human use of this space and both artificial and natural lighting.

There are roosting opportunities for bats against the ridge board and in the crevices in the stone wall internally.

In order to determine if bats were using the first floor area a remote bat detector and Trail camera were installed from the 15th July 2020 to the 1st September 2020. No bats were recorded. An emergence survey was undertaken on the 1st September 2020 and it recorded a Common pipistrelle bat entering and emerging from the ground floor stables foraging, but the bat did not emerge from the building. Bats are not using the building as a place of shelter.

The proposal is to retain the existing roof and bitumous underfelt in any conversion.

The conversion of the barn to a dwelling will affect nesting birds. Replacement nesting opportunities for swallows and the wrens using the building can be provided in the adjacent part of the building that is to be retained as a barn. Also Swallows are nesting in the coal bagging plant adjacent to the site and this will be retained.

The site has low value to biodiversity and comprises predominantly hard standing with small areas of rough grassland. Proposed plans include the creation of gardens with amenity grassland, trees and ornamental shrubs which will result in an increase in biodiversity for the site.

Impacts on bats.

The conversion of the property will have a negligible impact on bats due of the loss of the roosting against the ridge board or in the stone wall crevices. The method of working below must be followed to ensure that the potential for disturbing or harming bats, however small, is minimized and avoided.

There is no loss of habitat from the proposed development and there will be no impact on habitat, forage or commuting routes from the proposed development. Enhancements for bats.

Records and the emergence survey data show that there are populations of crevice dwelling bats locally. New roosting opportunities for these species of bats can be created when the new dwelling is built if planning permission is granted, to meet the requirements of the National Planning Policy Framework (2018).

Roosting for bats can be created in the adjacent barn by fixing a bat box to the wall internally. The ridge board would be available for bat roosting.

There should be no direct illumination of the new bat roosting opportunity. Lighting around the site will be by low wattage down lights at low level to provide security and safety lighting for the dwelling and service area. This lighting will be set no higher than the head height of the ground floor windows and will minimise the possible disturbance to bats in this area. Any security lighting will use PIR’s to ensure they turn off automatically once the movement has ceased. The method of working has been set out so that it can printed and handed to contractors on site.

**Method of working.**

There is no evidence of bats using the buildings as a place of shelter but it is possible that individual bats may use the possible roosting site against the ridge board or in the stone wall crevices internally at different times of year. Because of this possibility a method of working should be put in place when there are contractors on site. This would cover work to the roof or demolition where there was access for bats.

The common species of bats that are likely to roost in buildings of this nature and are evidenced from the regional records, are crevice dwelling bats, such as the Common Pipistrelle. These bats are small and can use accesses as little as 50mm x 20mm. when found in buildings they appear no bigger than a thumb and have dark brown fur.

It is common to find bat droppings in places used by bats. These are small and often confused with mouse droppings. It is possible to distinguish between them as mouse droppings are hard whereas bat droppings, being only insect remains, crumble when rubbed between the fingers.

The other species of bat that may possibly be found on site is the Brown Long Eared bat. These are a medium sized bat, larger than a Pipistrelle with very long ears that meet in the centre of the head. These bats may be found in crevices in the brickwork, behind ridge boards or in splits in the larger roof timbers.

- When tiles are removed they should be lifted away from the roof and not slid or twisted to avoid injuring any bats roosting beneath the tiles.
- Ridge tiles should be lifted without sliding so as to avoid injuring any bats roosting beneath them.
- If a bat is found under a roof tile or ridge tile, the tile should be carefully replaced and work in that area stopped until such time as a licensed bat worker can attend the site.
- The bat can then be removed to a place of safety until such time that it can be released at night.
- The demolition of any part of the building where bats could potentially roost should be by hand. This includes the removal of roof tiles, ridge tiles, soffits, gutter fascia boards and hanging tiles. If a bat is found the work should be stopped immediately and a bat worker called to come and deal with the bat. The bat should not be handled except by a licensed bat worker. Any bats found will be taken into care for release on site later dependent upon the time and weather.
- Bats discovered during the winter period will be taken into care, feed and kept healthy until they can be released on site in the Spring.
- Bats will not be released on site until evening temperatures are consistently above 6°C, at least three nights, the wind is light, and there is no rain.
- Bats taken into care over the winter will be released to the new roost opportunities in Spring if they are available using the same release criteria as above.

Legislation concerning bats.

The Wildlife and Countryside Act 1981 (WCA) protects bats and their roosts in England, Scotland and Wales. Some parts have been amended by the Countryside and Rights of Way Act 2000 (CRoW) which applies only in England and Wales, and by the Nature Conservation (Scotland) Act 2004 which applies in Scotland.

The Conservation of Habitats and Species Regulations 2010 (better known as the Habitats Regulations) implements the Council Directive on the Conservation of Natural Habitats and of Wild Fauna and Flora. All bats are listed as 'European protected species of animals'.

It is an offence for any person to:

- Deliberately capture, injure or kill a bat.
- Intentionally or recklessly disturb bats, where that disturbance may significantly affect the ability of those bats to survive, breed, rear or nurture their young, or is likely to significantly affect the local distribution or abundance of any bat species, whether in a roost or not.
- Damage or destroy a place of shelter (roost) of a bat, be that a resting or breeding place.
- Possess a bat, whole or in part, alive or dead.
- Intentionally or recklessly obstruct access to a roost.
- Sell or offer for sale or exchange whole or parts of bats, alive or dead.

The fine for committing an offence is £5,000 per bat.

If a bat is found on site, work should stop in the area where the bat was found and the contractor should call the Bat Consultant; S. Christopher Smith 07967636115. Breathable Roofing Membranes - Info Sheet

What are they?

- Traditional roofing felt was bitumen based
- Modern membranes are made from very fine and long plastic fibres that are spun into thin sheets. They can be single ply or have various layers to provide a more complex membrane.
- They are known as Breathable roofing membranes or Vapour permeable underlay’s (BRMs/VPUs)

Why are they used?

- Modern houses are designed to be more energy efficient, meaning they tend to be warmer.
- Along with human activities this means increased levels of water vapour in the air
- When this passes up into the cold roof space, it forms condensation, which can lead to problems
- In the past gaps would have been left near the ridge and eaves to allow ventilation, but increased insulation often means this isn’t possible. A breathable membrane aids this as it allows water vapour to pass out of the loft into the external air

Who Makes them?

- When most people talk about BRMs, they will call it Tyvek as this is the most famous brand name
- There are over 70 products in the UK alone, made by 20+ companies – never assume the product is Tyvek unless there is proof.

Potential Problems

- There have been reports of bats becoming entangled in fibres pulled from the membranes
- Possibility of Temperature and humidity change
- A lot of membranes are white or brightly coloured

Advice

- At present we cannot recommend specific brands that are considered safe for use in bat roosts, as such it is recommended that bitumen felt be used where possible
- It is not against the law not to install a BRM
- If the planner insists on a BRM, suggest a dark coloured and reinforced membrane

Bibliography.

Bat Mitigation Guidelines, A.J. Mitchell-Jones, English Nature, 2004. Bat Surveys for Professional Ecologists, Good Practice Guidelines, Bat Conservation Trust, 2016. Bats and Lighting in the UK, Bat Conservation Trust and Institution of Lighting Engineers, 2007. Bats and Traditional Buildings, English Heritage et al, 2009. Bats and lighting, Alison Fure, The London Naturalist, No 85, 2006. Effect of street lighting on bats, Matt Emery, Urbis Lighting Limited, January 2008. Barns owls and rural planning applications, Barn Owl Trust and Natural England, 2009. Bat Tree habitat Key, Henry L Andrews et al, 2012. British Bat Calls, Jon Russ, 2012. Street lighting disturbs commuting bats, Stone et al, Current Biology, 2009. Acoustic Ecology of European Bats, M. Barataud, 2015 Bats of Britain and Europe, C. Dietz and A. Keifer, 2016. ILP Guidance Note 8 Bats and Artificial Lighting, 2018 Is that a Bat?, N Middleton, 2020

S. Christopher Smith MRICS MSc CEnv. Appendix 1.

Roost Types as designated by Natural England and the Bat Surveys for Professional Ecologists, Good Practice Guidelines.

A. Day roost: a place where individual bats, or small groups of males, rest or shelter in the day but are rarely found by night in the summer. B. Night roost: a place where bats rest or shelter in the night but are rarely found in the day. May be used by a single individual on occasion or it could be used regularly by the whole colony. C. Feeding roost: a place where individual bats or a few individuals rest or feed during the night but are rarely present by day. D. Transitional / occasional roost: used by a few individuals or occasionally small groups for generally short periods of time on waking from hibernation or in the period prior to hibernation. E. Swarming site: where large numbers of males and females gather during late summer to autumn. Appear to be important mating sites F. Mating sites: sites where mating takes place from later summer and can continue through winter. G. Maternity roost: where female bats give birth and raise their young to independence. H. Hibernation roost: where bats may be found individually or together during winter. They have a constant cool temperature and high humidity. I. Satellite roost: an alternative roost found in close proximity to the main nursery colony used by a few individual breeding females to small groups of breeding females throughout the breeding season. J. Other – Explain what the roost type is if not one of the above (it is recognised that roost types are interchangeable and not always easy to classify according to the nuances of certain species).